Still scrambling? Here are a couple of guidelines for how to go about filing for an extension on your tax return and address a late filing if you owe income tax:

How to file: Tax returns are due by midnight Monday. If you're going to miss the deadline, file a request for an extension with the Internal Revenue Service. The IRS accepts extension requests several ways: by mail, via tax-preparation software, through a paid tax preparer or online via the IRS website, www.irs.gov.

Select the right form: To request the extension, you must fill out IRS Form 4868, which is available on the IRS website, through most tax preparation software, as well as in public libraries and post offices.

If you opt to mail in the form, it has to be postmarked by Monday to be considered on time. Forms filed online on the IRS website or by using tax software can be sent in as late as 11:59 p.m. CDT Monday. One bonus of filing online is the IRS will confirm receipt of the request form right away.